Limits...
Progressive migration and anagenesis in Drimys confertifolia of the Juan Fernández Archipelago, Chile.

López-Sepúlveda P, Takayama K, Greimler J, Crawford DJ, Peñailillo P, Baeza M, Ruiz E, Kohl G, Tremetsberger K, Gatica A, Letelier L, Novoa P, Novak J, Stuessy TF - J. Plant Res. (2014)

Bottom Line: A common mode of speciation in oceanic islands is by anagenesis, wherein an immigrant arrives and through time transforms by mutation, recombination, and drift into a morphologically and genetically distinct species, with the new species accumulating a high level of genetic diversity.Drimys confertifolia shows a wide genetic variation within populations on both islands, and values of genetic diversity within populations are similar to those found within populations of the continental progenitor.The genetic results are compatible with the hypothesis of high levels of genetic variation accumulating within anagenetically derived species in oceanic islands, and with the concept of little or no geographical partitioning of this variation over the landscape.

View Article: PubMed Central - PubMed

Affiliation: Departamento de Botánica, Universidad de Concepción, Casilla 160-C, Concepción, Chile.

ABSTRACT
A common mode of speciation in oceanic islands is by anagenesis, wherein an immigrant arrives and through time transforms by mutation, recombination, and drift into a morphologically and genetically distinct species, with the new species accumulating a high level of genetic diversity. We investigate speciation in Drimys confertifolia, endemic to the two major islands of the Juan Fernández Archipelago, Chile, to determine genetic consequences of anagenesis, to examine relationships among populations of D. confertifolia and the continental species D. winteri and D. andina, and to test probable migration routes between the major islands. Population genetic analyses were conducted using AFLPs and nuclear microsatellites of 421 individuals from 42 populations from the Juan Fernández islands and the continent. Drimys confertifolia shows a wide genetic variation within populations on both islands, and values of genetic diversity within populations are similar to those found within populations of the continental progenitor. The genetic results are compatible with the hypothesis of high levels of genetic variation accumulating within anagenetically derived species in oceanic islands, and with the concept of little or no geographical partitioning of this variation over the landscape. Analysis of the probability of migration within the archipelago confirms colonization from the older island, Robinson Crusoe, to the younger island Alejandro Selkirk.

Show MeSH

Related in: MedlinePlus

Geographical position of populations sampled of Drimys winteri and D.andina in continental Chile (a) and Drimys confertifolia in Robinson Crusoe (b) and Alejandro Selkirk (c) Islands
© Copyright Policy - OpenAccess
Related In: Results  -  Collection


getmorefigures.php?uid=PMC4300435&req=5

Fig1: Geographical position of populations sampled of Drimys winteri and D.andina in continental Chile (a) and Drimys confertifolia in Robinson Crusoe (b) and Alejandro Selkirk (c) Islands

Mentions: An appropriate group of islands in which to study anagenetic speciation and migration is the Juan Fernández Archipelago, located in the Pacific Ocean 667 km W of continental Chile (33°S/78–80°W, Fig. 1). The archipelago consists of two main islands, Robinson Crusoe (=Masatierra) and Alejandro Selkirk (=Masafuera), separated by 181 kms. At present the islands are approximately of equal size (50 km2, Stuessy 1995), but they differ in geological age, c. 4 million years old for Robinson Crusoe Island and 1–2 million years old for Alejandro Selkirk Island (Stuessy et al. 1984). The native vascular flora of the archipelago includes 75 families, 213 genera, and 361 species, with a 12 % endemism at the generic level, and 60 % at the specific level (Marticorena et al. 1998).Fig. 1


Progressive migration and anagenesis in Drimys confertifolia of the Juan Fernández Archipelago, Chile.

López-Sepúlveda P, Takayama K, Greimler J, Crawford DJ, Peñailillo P, Baeza M, Ruiz E, Kohl G, Tremetsberger K, Gatica A, Letelier L, Novoa P, Novak J, Stuessy TF - J. Plant Res. (2014)

Geographical position of populations sampled of Drimys winteri and D.andina in continental Chile (a) and Drimys confertifolia in Robinson Crusoe (b) and Alejandro Selkirk (c) Islands
© Copyright Policy - OpenAccess
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC4300435&req=5

Fig1: Geographical position of populations sampled of Drimys winteri and D.andina in continental Chile (a) and Drimys confertifolia in Robinson Crusoe (b) and Alejandro Selkirk (c) Islands
Mentions: An appropriate group of islands in which to study anagenetic speciation and migration is the Juan Fernández Archipelago, located in the Pacific Ocean 667 km W of continental Chile (33°S/78–80°W, Fig. 1). The archipelago consists of two main islands, Robinson Crusoe (=Masatierra) and Alejandro Selkirk (=Masafuera), separated by 181 kms. At present the islands are approximately of equal size (50 km2, Stuessy 1995), but they differ in geological age, c. 4 million years old for Robinson Crusoe Island and 1–2 million years old for Alejandro Selkirk Island (Stuessy et al. 1984). The native vascular flora of the archipelago includes 75 families, 213 genera, and 361 species, with a 12 % endemism at the generic level, and 60 % at the specific level (Marticorena et al. 1998).Fig. 1

Bottom Line: A common mode of speciation in oceanic islands is by anagenesis, wherein an immigrant arrives and through time transforms by mutation, recombination, and drift into a morphologically and genetically distinct species, with the new species accumulating a high level of genetic diversity.Drimys confertifolia shows a wide genetic variation within populations on both islands, and values of genetic diversity within populations are similar to those found within populations of the continental progenitor.The genetic results are compatible with the hypothesis of high levels of genetic variation accumulating within anagenetically derived species in oceanic islands, and with the concept of little or no geographical partitioning of this variation over the landscape.

View Article: PubMed Central - PubMed

Affiliation: Departamento de Botánica, Universidad de Concepción, Casilla 160-C, Concepción, Chile.

ABSTRACT
A common mode of speciation in oceanic islands is by anagenesis, wherein an immigrant arrives and through time transforms by mutation, recombination, and drift into a morphologically and genetically distinct species, with the new species accumulating a high level of genetic diversity. We investigate speciation in Drimys confertifolia, endemic to the two major islands of the Juan Fernández Archipelago, Chile, to determine genetic consequences of anagenesis, to examine relationships among populations of D. confertifolia and the continental species D. winteri and D. andina, and to test probable migration routes between the major islands. Population genetic analyses were conducted using AFLPs and nuclear microsatellites of 421 individuals from 42 populations from the Juan Fernández islands and the continent. Drimys confertifolia shows a wide genetic variation within populations on both islands, and values of genetic diversity within populations are similar to those found within populations of the continental progenitor. The genetic results are compatible with the hypothesis of high levels of genetic variation accumulating within anagenetically derived species in oceanic islands, and with the concept of little or no geographical partitioning of this variation over the landscape. Analysis of the probability of migration within the archipelago confirms colonization from the older island, Robinson Crusoe, to the younger island Alejandro Selkirk.

Show MeSH
Related in: MedlinePlus